Regarding wire bonding, there is a technique of, upon wedge bonding of wires on surfaces of leads, using a capillary having: a first pressing-down surface in a curved surface shape formed around an edge at a tip; and a second pressing-down surface formed in circle around the first pressing-down surface, and forming a flattened portion to the capillary by further increasing the pressing down amount so that bonding force to the surfaces of leads is strengthened. The technique is described in, for example, Japanese Patent Application Laid-Open Publication No. 2000-091372 (Patent Document 1).